1. Field of the Invention
The present invention relates to a method of specifying frame numbers of an elongated photographic film. In the elongated photographic film position specifying areas are evenly set in the longitudinal direction of the film for including therein numbers of image frames recorded on the film at a certain interval in the longitudinal direction. And in the elongated photographic film a frame number within a position specifying area is specified as the frame number of an image frame if the center of the recorded image frame is present in this position specifying area.
2. Related Art
In a photographic film such as a negative, frame numbers are provided in the vicinity of each of the image frames of the film. Bar codes corresponding to the frame numbers are provided in the vicinity of the frame numbers and are designed to be read by a sensor. When one of the bar codes is read by the sensor and the corresponding frame number is specified, one of the image frames is distinguished from others.
Each bar code itself is positioned on the centerline of an area which is specified by the bar code. The area to be specified by the bar code is so called as "a position specifying area" hereinafter. When the center of an image frame is in the area, the frame number of the image frame is determined to be the frame number within that area.
This arrangement will be described with reference to FIG. 4. In the example shown, a negative 50 is a 35 mm film in which image frames are formed by taking photographs and are recorded in full-size. Bar codes 52 are provided at even intervals on the edge portion of the negative 50 on one widthwise side thereof (i.e., on the upper edge portion as viewed in FIG. 4). The bar codes 52 are arranged in the sequence of 0, 0A, 1, 1A, 2, 2A, 3 . . . , from the left side to the right. In this way, the bar codes 52 are provided to be also applicable to half-size image frames. The position specifying area corresponding to each bar code 52 is defined by a range indicated by one-dot chain lines in FIG. 4. If image frames 54 are continuously recorded in full-size, the centers of the image frames 54 are normally present within alternate areas. For instance, the centers are positioned at the positions indicated by marks and by broken lines in FIG. 4. In the condition shown in FIG. 4, therefore, the numbers of the image frames 54 are specified as 0A, 1A, 2A, . . . from the left. If the negative 50 were set in the camera in a different manner, the numbers of the image frames 54 may be specified as 1, 2, 3, . . . from the left. In either case, the specified frame numbers comprises either integers alone or integers followed by the symbol "A" alone. Thus, the frame numbers are specified in the form of a sequence of numbers or a sequence of numbers followed by symbols and, hence, have a certain regularity which facilitates determination of the front-rear relationship between the frame numbers in the sequence.
When frame numbers have been specified in this manner, they are each printed on the reverse surface of the printed paper, so that the numbers are used to select certain image frames 54 out of those originally provided in the negative 50 when reprints or the like are requested.
The above-described arrangement will encounter no problem when all the centers of the image frames 54 are present at even intervals. However, the position of the centers of the image frames may deviate if there was any variation in the distance by which the film was wound during photography. A similar deviation may result from deviation in the reading position during the reading of the bar codes 52. In such cases, particularly if the centers of the image frames 54 are present in the vicinity of the borders of the areas, the following problem is encountered. For instance, as shown in FIG. 5, the centers of the image frames 54 may be present within the areas corresponding to frame numbers 0, 1A, 2, 3, . . . , from the left (see the positions indicated by marks and broken lines in FIG. 5). In this way, the frame numbers will lack regularity. With such an irregularity of frame numbers, when the frame numbers corresponding to the bar codes 52 read are printed on the reverse surface of the printing paper, the client may find them to be rather strange. If reprints are requested by the client, it would then be necessary to check all the pieces of printing paper, which is a cumbersome operation.